Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already flag destructiveHint=true and idempotentHint=true; the description reinforces the idempotency ('or return the existing') and adds non-obvious context the annotations cannot convey — the link is public and viewable without sign-in, so user approval is required. It does not describe what happens to prior links or rate limits, keeping it short of a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the action and its semantics, followed by the safety warning and the revoke route. No filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter tool with full annotation coverage and no output schema, the description covers purpose, safety, and undo. The return shape (a URL vs. an object) is only implied by 'preview link', which is a minor gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the only parameter is documented ('Post UUID — from list_posts'), so the baseline is 3. The description adds only the ownership scoping ('one of the user's posts'), which is minor beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Create ... public preview link for one of the user's posts') and even clarifies the idempotent create-or-return semantics. It explicitly names the sibling that undoes it (unshare_post), so an agent can place it in the family without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a clear condition for use (sharing a post publicly) and an explicit requirement to get the user's approval first, plus the revoke path via unshare_post. It does not enumerate alternatives for the same operation, but the when-to-use context is unambiguous.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.